1. Space Camp is awesome. Congratulations to your son!
2. I definitely am down for a beer and dinner or lunch. Just say when.
3. I love hiking. Huntsville, Chattanooga, and Gatlinburg are great for hiking. Huntsville has Monte Sano State Park and many Land Trust of North Alabama parks. They are all great. To be perfectly honest, I pulled up a list of tourist attractions for Huntsville and while everything on it is great those attractions are great for a family that lives in the area and visitors, none of those are worthy of planning your vacation around; except space camp of course. https://www.tripadvisor.com/Attractions-g30620-Activities-Huntsville_Alabama.html
I live in Huntsville so our trails are my hangouts and I love them but they aren’t the Smokey Mountains. That’s Gatlinburg and Smokey Mountain National Park is next level. Not too far from Gatlinburg you could also hit Asheville, NC which is home to a lot of good breweries including Sierra Nevada. Asheville has a lot more to offer than beer.
Chattanooga is a great town for a day trip from Huntsville. Lots to do. They have a great aquarium, lots of cool restaurants, some cool attractions, and their downtown is right on the Tennessee River.
You already know about Nashville.
The Gulf Coast is 5.5-7 hours south of Huntsville depending on traffic and where you are going. Gulf Coast beaches are white sand and the water is usually clear and emerald green. Destin, Florida is the best place to go. Beaches in or near Destin: 30-A is upscale and very nice, Crystal Beach and Miramar Beach are a bit more affordable but also excellent.
Atlanta, GA...kind of cool but nothing really drawing you in
Knoxville, TN...good for lunch or Football game in the fall
Tuscaloosa, AL...Great football
Auburn, AL...are you lost?
New Orleans...probably too far from Space Camp
Tim Ford, TN...rent a lake house
Guntersville, AL...rent a lake house
Mentone, AL...stay the night in a B&B, day trip to the Little River Canyon, and have dinner at the Wildflower Cafe. Great day.
PS. The cafeteria at Space Camp has a sign that says Get More Space at the University of Alabama in Huntsville. I hear there is an amazing professor there named Tommy Morris